Improvement in power-hammers



PATENT OFFICE.

LAWRENCE BRADY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO l MICHAEL HAYDON, OF SAME PLACE.

IMPROVEMENT IN POWER-HAM MERS.

Specification forming part of Letters Patent No. 217,327, dated July 8, 1879; application filed september 23, 1ers.

To all whom it may concern:

Beit known that I, LAWRENCE BRADY, of

' Philadelphia, in the county of Philadelphia i means for applying power from a driven shaft to actuate the hammer employed in heading bolts, which hammer has heretofore been worked by means of a treadle depressed by the foot of the operator.

My improvements consist in the peculiar construction and combination of parts hereinafter set forth.

Referring to the accompanying drawings, A indicates the anvil, recessedat a for the reception of the bolt-blank, and having a projection, al, with two arms, a2 a2, which form a support for the hammer-frame B. Said frame B consists of the two uprights b b, with crossrod b. C is the hammer, and c its handle, made fast in a rock-shaft, D, which has its bearings in the supports b b. D is a short arm which projects forwardly from the rockshaft l). E is a shaft mounted on a suitable stand, E', and F is a loose pulley there0n,-re ceiving its motion from a shaft, G, through the medium of belt g. H is a friction-clutch on the shaft E, adapted. to be slid into and out of clutch engagement with the pulley F by means of a lever, I. Said lever is con` nected at one of its ends or on one side of the clutch with a rod, K, which passes through a yoke, lr, in which is a spiral spring, lc', the office and tendency of which are to draw the clutch out of engagement with the pulley F. The opposite end of said lever is connected by a rod, l, with one arm, m, of an elbow-lever, M, pivoted at m2 to the anvil-support A. 'The other arm, m, of said lever Mis formed or provided with a foot-rest, m3. By depressing the i arm m1 with his foot, the operator standing by the side of the anvil is enabled to bring the clutch H into engagement with the pulley F, and thereby to revolve the shaft E. 0n releasing the footpressure from said arm ml, the clutch is drawn out of engagement with the pulley F, whereupon the shaft E ceases to re- -volve. E is a crank on the shaft E, having a wrist-pin, e, which moves between a keeper, N, and a lever, O, to which said keeper is fastened. Said lever O is pivoted at o, and connected bya connecting-rod, o', with the arm D on the shaft l). Accordingly, when the shaft E is revolved, the hammer C is caused to strike, its lifting after each stroke being ach complished by a spring, P, sustained overhead at p p, and connected by a rod or chain, p', with the arm D. Q is a buffer-spring, of any appropriate construction, secured on the under side of the anvil projection al, and designed to break the force or receive the imi pact of the outer end of the lever O on its upward movement under the iniluence of the spring P.

The successive blows of the hammer on the 4blank have the eifect of upsetting the latter into the matrix in the anvil, the height or upward projection of such blank being thus diminished. Now, to graduate the blows of the hammer according to the extent of projection of the blank, and to avoid injurious straining between the wrist-pin e and keeper N on the first two blows or strokes of the hammer, (three strokes being the number required to form the head of the bolt,) a yielding plate, N', is located in the keeper N, forming the bottom or way on which the said wrist-pin e moves on the motion of the crank fromits front to its back center. Said plate is fulcrumed at u and formed with a tongue, u', which has liberty of vertical motion in a slot, n2, formed in the front wall of the keeper N.

It is a stiff rod passing through the lever O below the center ofthe plate N', having a head, r, on which said plate rests. S is a bracket or hanger secured to the under side of the lever O, and holding a spiral spring, '13, through which the rod R passes. s s are nuts on the rod R above the spring T.

The operation is as follows; The operator,

standing by the side ofthe anvil, 'places a blank in the matrix a. He then depressesv the arm ml with his foot, bringing the clutch into engagement with the pulley F, and causing` the shaft E to revolve and the hammer C to strike. As soon as the required number of strokes has been made, he relaxes the footpressure on the arm m1, whereupon the clutch is'moved out of engagement with the pulley F, and the hammer ceases to strike. The bolt is then thrown out of the matrix by the usual plunger appliance and a new blank inserted. The spring P not only assists in raising the hammer when the crank-shaft is working, but operates to lift such hammer after the motion ot' said shaft ceases. Thus, for example, if the shaft should be stopped just as the nal blow is made or accomplished, the hammer, were it not for the spring P, would remain down and would prevent the discharge of the bolt from the matrix; but the spring P in such a case raises thehammer and holds it in its elevated posit-ion ready to make a downward stroke the moment thefshaft E is again revolved.

With reference to the purpose and effect of 'the buffer Q, it will be observed that While the primary object of this device is to resist or cushion the blow or upward thrust of the lever 0, its 'quality of resistance is such as to not prevent the lever from rising to the limit required by the throw of the crank.- The buffer yields after the impact of the lever, and thus entirely avoids the strain upon or locking of the crank which would ensue if the buffer were of limited yielding capacity.

What I claim as my invention is- 1. 'Ihe combination, with the hammer C c, of the shaft E, crank E', lever O, yielding plate n1,liftingspring P, and mechanism, substantially as described, between said lever and lifting-spring, for communicating motion therefrom to the hammer, as and for the pur-` pose set forth.

2. The combination, with the lifting-spring P, rock-shaft D, lever O, and crank-shaft E, ot' the buer Q, substantially as shown and described. 3. In combination with lever O and crank E, the yielding plate N in keeper N, rod R, and spring T, substantially as shown and described.

In testimony that I claim the foregoing I have hereunto set my hand this 19th day of September, 1878.

LAWRENCE BRADY. 

